This research will apply advanced MR techniques, Projection Reconstruction (PR MR), Compact Spin Echo (CSE), and warp Spoiled GRASS (SPGR), to three models of lung disease: pulmonary metastases (focal nodules), pulmonary perfusion abnormalities (emboli) and chronic diffuse lung disease (idiopathic pulmonary fibrosis; IPF). The objectives are to test the sensitivity and specificity of these MR sequences compared with current "gold standards" provided by CT for nodules, and by radionuclide scans for pulmonary emboli. We will also evaluate the utility of these MR sequences in identifying IPF and in distinguishing inflammatory from fibrotic stages of the disease. Two independent radiologists, blind to the "gold standard" images, will evaluate: (1) PR MR, CSE and conventional MR images for number, size and location of pulmonary nodules in humans, (2a) PR MR and SPGR images for emboli in a canine model and in humans, (2b) CSE images for susceptibility changes in perfusion defects; and, (3) PR MR, CSE and conventional MR images in patients with IPF and healthy control subjects. Results for each imaging modality will be compared with the "gold standard" using Wilcoxin and Spearman Ranked Correlation tests. The success of this MR research will directly lead to improved, noninvasive and cost-effective alternatives to existing diagnostic lung imaging procedures that currently depend on ionizing radiation.